Venezuela's socialist president Nicolas Maduro accused the right-wing governments of Chile, Colombia and Mexico on Monday of helping "terrorists" who tried to kill him during a drone attack in early August.The three countries refuted Venezuela's accusations that they were linked to the attack, which used drones carrying explosives during a military parade, in the latest spat between diplomatically isolated Caracas and Latin America.Maduro showed a video of a young Venezuelan man, identified as Henryberth Rivas, who said in a televised broadcast on Monday night he participated in the drone attack . . .